Floodlights do the job the marking lights cannot: they light the deck surface itself, so
that once an aircraft is down, people can work. Passengers disembark, baggage and freight are
handled, refuelling happens, and none of that is possible by the light of a perimeter outline.
The floodlights are also what let the crew see the deck condition - ice, spillage, loose
equipment - before an aircraft arrives.
Q-Aviation's explosion-proof floodlight is a CAP437 compliant 5000 candela unit for hazardous
areas, with a 15,000 candela high-intensity version available. Having both in the range is the
useful part: output requirement scales with deck size and mounting height, so a large deck lit
from a high mounting needs the high-intensity unit while a smaller deck would be over-lit by
it.
Over-lighting is a genuine hazard rather than a waste, and it is why floodlights are
controlled separately from the marking lights. A pilot approaching at night has dark-adapted
vision, and a deck lit to daylight levels destroys it - along with the ability to see the
perimeter and TD/PM lighting the approach is actually flown to. Standard practice is that the
floodlights are off or low during the approach and brought up once the aircraft is down, which
is exactly why Q-Aviation's control systems put them on their own switched group.
Aiming is the other half of getting this right, and it is a design decision. Floodlights
have to illuminate the working area without shining into the approach path or into the
pilot's eyes, which usually means mounting them at the deck edge and directing them inward and
downward. A floodlight that has been re-aimed by someone who found the deck too dim can quietly
make the deck unusable at night.
The explosion-proof construction and LED source follow the rest of the range. LED matters
particularly for floodlights because they are the highest-power fittings on the deck: efficiency
determines the load the control system and the supply have to carry, and instant full output
means there is no warm-up delay between the decision to light the deck and the deck being
lit.
